PROJECT SUMMARY Alzheimer's Disease and Related Dementias (ADRD) are among the most profoundly disabling and costly of all health conditions and the 5th leading cause of death. Family caregivers are at the forefront of managing ADRD across the continuum of care but are not routinely included in discussions about prognosis and are often poorly prepared to engage in surrogate decision-making. Compared to older adults without ADRD, those with ADRD are less likely to complete an advance directive and to formally designate a surrogate decision-maker, and are at heightened risk for unnecessary suffering and burdensome end-of-life care. Advance care planning seeks to improve communication about individual values, goals, and preference for care, but typically targets a specific decision, most often in the inpatient hospital or nursing home. Few interventions target advance care planning in primary care, which is where most persons with ADRD are initially diagnosed and medically managed. We propose a developmental study of a multicomponent communication intervention, referred to as SHARE, to proactively engage family caregivers and support advance care planning in primary care. Intervention components include: 1.) a letter from the primary care practice introducing a new advance care planning initiative, 2.) person-family agenda-setting to align patient and family perspectives regarding the role of the family member in primary care interactions and stimulate interest in advance care planning, 3.) ongoing access to a nurse or social worker trained to lead advance care planning conversations, 4.) facilitated registration for the patient portal (for patient and family) to enable and extend electronic interactions and information access to family caregivers. Study Aims reflect two phases that aligned with Stage 1A (refinement) and Stage 1B (testing) of the NIH behavioral intervention development Stage Model. First, we use a user- centered process to refine SHARE with input from primary care stakeholders (physicians, nurse practitioners, social workers, staff), patients with ADRD, and their family caregivers. We will iteratively adapt and pre-test the protocol in 10-15 patient-caregiver dyads at 1 primary care practice. Aim 1 will yield a testable intervention protocol. Second, we will partner with 4 primary care practices to conduct a two-group randomized Stage 1B trial in which 124 dyads receive a control protocol of usual care and 124 dyads receive the intervention protocol. We hypothesize that intervention (versus control) family caregivers will report better quality of communication at 6 months (primary outcome) and among patients who die, that intervention (versus control) patients will experience higher quality end-of-life care and bereaved family caregivers will be better prepared for surrogate decision-making and report fewer symptoms of anxiety and depression (secondary outcomes). We will qualitatively assess the implementation context to identify factors that may affect dissemination of the intervention. Aim 2 will provide critical information and evidence to facilitate subsequent dissemination.